Anti-Swing Control Study Of Shipboard Cranes

Tower cranes are used in a wide range of civil and military applications due to their operational flexibility and wide range of operations.In combination with cargo ships and other carriers,tower cranes can be used as shipborne cranes to efficiently solve the problem of transferring and transporting bulky goods in coastal ports and on the sea.However,external factors such as sea winds and waves can interfere with the stability of the vessel,resulting in inefficient and even dangerous shipborne crane operations.At the same time,from the control point of view,the tower crane itself is a typical underdriven system,making the shipborne crane system have stronger variable coupling characteristics and more complex motion characteristics,which poses new challenges to the system control design.To address these issues,this paper presents an in-depth study of the rapid positioning of crane translation and jib rotation,load swing suppression and three-dimensional hull disturbance.From the experimental platform of the shipborne crane,the system dynamics model is constructed and its dynamics characteristics are analysed.Based on this,two control algorithms for shipborne cranes are designed,and numerical simulations and hardware experiments are carried out.The main research for this paper includes:1.Hardware experimental platform construction and dynamics modelling.In this project,a shipborne crane experimental platform is built with reference to the actual working scenario,which consists of a tower crane experimental platform and a ship hull simulator together.Among them,the tower crane experimental platform is responsible for simulating the transfer of cargo by shipborne crane,and the hull simulator is responsible for simulating the sea surface disturbance.The platform realises the functions of hull simulation,motion simulation and data interaction.On this basis,Lagrange’s equations are used to build a model of the dynamics of the tower crane and the shipborne crane that can reflect the system’s motion characteristics.The modelling process solves the problem of missing modelling of the longitudinal sway direction of existing shipborne cranes,and the establishment of the two types of models lays the foundation for control design.2.Tower crane control design under minor hull disturbances.In some small near-port areas,due to the relatively fixed hull,the ship crane by external sea wind and waves and other disturbance factors small.In the control design process the hull oscillation is regarded as an external disturbance to the system and the control design of the tower crane is carried out.In this paper,based on the tower crane hoisting model,a coupled error auxiliary function and a non-linear controller based on the Lyapunov function are designed from the stability of the system to achieve full process decoupling and synchronous control of the crane/jib motion and load swing.3.Shipborne crane control design under three-dimensional hull disturbance.In some large ports or on the sea far from the coastline,the shipborne crane is affected by the sea wind and waves which cannot be ignored,and the control design process should take them as the main influencing factor.In this paper,an all-state observer is used for online observation of hull disturbances,which can change its structure according to the controller structure used in the system and ensure the stability and optimality of the observation.Based on the underdrive characteristics of the system,an inverse control algorithm is used to achieve the control objectives of accurate positioning and oscillation suppression by combining with the fullstate observer.4.Numerical simulations and physical experiments.A large number of numerical simulations,simulation experiments and physical hardware experiments have been carried out for the control schemes of the above two types of shipborne crane systems.From the comparison results,it can be obtained that the control algorithm proposed in this paper shows superior performance in terms of fast positioning of the crane translation and swing of the jib and fast suppression of load swing of the system.